air release valve
Photo by CC user Chris Smart on Flickr.

Also known as an air relief valve and a small orifice valve, an air release valve is an essential part of a pipeline structure and are commonly used to protect the efficiency of a system. Available in a wide variety of materials that help them to operate in conjunction with different applications, it’s no wonder why the air release valve has become such a popular piece of equipment. Read more to find out what these valves are and how they work.

What is an air release valve

Though it may sound a bit complicated, an air release valve is a valve that functions to release air that is trapped and collected at each high point that makes up a full pressured pipeline. What makes these valves interesting is that they can open up against any internal pressure felt. This is due to an internal lever that works to make the float force greater then the actual internal pressure within the pipe. Whenever an air pocket, or a group of air pockets, form in the valve, this greater force opens the orifice therefore releasing each and every air pocket. These valves are used in both clean water and sewage pipelines. Because they are small in size (at least the personal home grade ones), they’re also very easy to install as well.

Sometimes you’ll also find the need to have one or more dual valves in your system. These valves work to both get rid of large volumes of air from your system while also allowing air to re-enter the system after the pipe has been emptied.

How does an air release valve work

To get into a little more detail than what was stated above, an air release valve operates by using a ball float that floats near the surface of the valve. When the water line rises up to the valve top, the ball floats up with it, therefore closing the opening. This in turn pushes all of the air in the pipe out. When water is drained from the pipe, the ball float floats down toward the bottom again, which in turn allows air to flow back into the pipe.

In some cases you’ll find a combined valve that operates with a smaller float as well. This float works to let out smaller pockets of air before the main air release valve is used, therefore working to relieve pressure from the main ball float.

When working on a clean water or a sewage pipeline system it is important to make sure that you have all the necessary components needed to produce a constant flowing and efficiently working system. Though there are many different yet equally important aspects of a pipeline system, one of the most important features is the air release valve. Just remember that when searching for one to note that they are sometimes refereed to as air relief valves and small orifice valves, though they’re most commonly referred to simply as air release valves.